function encodeUtf8(string) {
  string = string.replace(/\r\n/g, '\n')
  let utftext = ''
  for (let n = 0; n < string.length; n++) {
    const c = string.charCodeAt(n)
    if (c < 128) {
      utftext += String.fromCharCode(c)
    } else if ((c > 127) && (c < 2048)) {
      utftext += String.fromCharCode((c >> 6) | 192)
      utftext += String.fromCharCode((c & 63) | 128)
    } else {
      utftext += String.fromCharCode((c >> 12) | 224)
      utftext += String.fromCharCode(((c >> 6) & 63) | 128)
      utftext += String.fromCharCode((c & 63) | 128)
    }
  }
  return utftext
}

const keyStr = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_='

export const encodeBase64 = function(input) {
  let output = ''
  let chr1
  let chr2
  let chr3
  let enc1
  let enc2
  let enc3
  let enc4
  let i = 0
  input = encodeUtf8(input)
  while (i < input.length) {
    chr1 = input.charCodeAt(i++)
    chr2 = input.charCodeAt(i++)
    chr3 = input.charCodeAt(i++)
    enc1 = chr1 >> 2
    enc2 = ((chr1 & 3) << 4) | (chr2 >> 4)
    enc3 = ((chr2 & 15) << 2) | (chr3 >> 6)
    enc4 = chr3 & 63
    if (isNaN(chr2)) {
      enc3 = enc4 = 64
    } else if (isNaN(chr3)) {
      enc4 = 64
    }
    output = output +
    keyStr.charAt(enc1) + keyStr.charAt(enc2) +
    keyStr.charAt(enc3) + keyStr.charAt(enc4)
  }
  return output
}

export const loginAndBack = function() {
  const url = top.location.href
  console.log('login and back with: ' + url)
  const urlEncoded = encodeBase64(url + '?auth_code=')
  const login = process.env.VUE_APP_LOGIN_API  + urlEncoded
  top.location.href = login
}

